Serving area interface


The serving area interface or service area interface is an outdoor enclosure or metal box that allows access to telecommunications wiring.

Alternate names

  • Access point
  • Cabinet
  • B-box
  • Cross box
  • Cross-connect box
  • Jumper wire interface
  • Outside plant interface
  • Pedestal
  • Primary cross-connection point
  • Secondary cross-connection point
  • '''Telecom cabinet'''

Function

The SAI provides the termination of individual twisted pairs of a telephony local loop for onward connection back to the nearest telephone exchange or remote switch, or first to transmission equipment such as a subscriber loop carrier multiplexer and then to the exchange main distribution frame.
In the United Kingdom, the components from the PCP onwards to the customer are known as "D-side", and from the PCP back to the MDF as the "E-side". In the United States, the connection back to the MDF is known as the F2 and/or the F1 pairs.
SAIs are used in suburban and low-density urban areas, serving some of the same purposes that manholes do in high-density urban areas. Besides a cross connect point, they sometimes contain a DSLAM or more rarely a remote concentrator or both.